Because people have an intuitive feeling about how much 1 kW is, because they use devices with a power rating in Watt and have a feel for how powerful a device is at what rating. People also know exactly what an hour is. So it makes sense to think about a device of 1kW running for 1 hour, people have a good sense of how much energy that is in daily use. Since most energy bills are also in terms of kWh, people also have a good sense about the costs of that energy.
Given the popularity of the unit, I think people like it, otherwise a different unit would have been used already.
Because the power draw of appliances is measured in watts, so a 60 watt light bulb when lit draws 60 watts of power over the course of one hour. So if I have roughly 100 lightbulbs at 60 watts hooked up to my house, then I’ll be using 6 kW of power each hour.
It tells us more information about the rate of use of that energy. It’s like the difference between a 2 lb sphere of uranium being exploded in a fraction of a second vs 2 lb lf uranium fuel in a reactor operating for however long that much fuel lasts for. Both contain the same amount of joules of energy at the end of the process, one just uses all of those joules in one go and the other slowly releases that energy over a longer period of time.
I can’t imagine why kWh would be more convenient than MJ though.
Because people have an intuitive feeling about how much 1 kW is, because they use devices with a power rating in Watt and have a feel for how powerful a device is at what rating. People also know exactly what an hour is. So it makes sense to think about a device of 1kW running for 1 hour, people have a good sense of how much energy that is in daily use. Since most energy bills are also in terms of kWh, people also have a good sense about the costs of that energy.
Given the popularity of the unit, I think people like it, otherwise a different unit would have been used already.
Because the power draw of appliances is measured in watts, so a 60 watt light bulb when lit draws 60 watts of power over the course of one hour. So if I have roughly 100 lightbulbs at 60 watts hooked up to my house, then I’ll be using 6 kW of power each hour.
It tells us more information about the rate of use of that energy. It’s like the difference between a 2 lb sphere of uranium being exploded in a fraction of a second vs 2 lb lf uranium fuel in a reactor operating for however long that much fuel lasts for. Both contain the same amount of joules of energy at the end of the process, one just uses all of those joules in one go and the other slowly releases that energy over a longer period of time.